The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 10, 2007
Filed:
Aug. 13, 2003
Masayuki Ito, Richmond, CA (US);
Fumio Arakawa, Kodaira, JP;
Mark Hill, Bath, GB;
Renesas Technology Corp., Tokyo, JP;
Abstract
In performing address translation from a virtual address space to a physical address space, when the virtual address space is divided into an area (P), which is subjected to the address translation by TLB, and areas (Pand P), which are fixedly mapped to the physical address without being subjected the address translation, future extension of the physical address become difficult. A data processor comprises an address translation unit ATU that receives virtual address output from the CPU and outputs a physical address; the ATU includes a first translation lookaside buffer UTLB, a second translation lookaside buffer DTLB, a control circuit TLB_CTL that selects one of a first and a second translation lookaside buffers and performs address translation in accordance with an area of an address space in the virtual address. Since it is adapted so that the areas (Pand P), which are conventionally mapped fixedly by hardware, are subjected to the address translation by the DTLB, it is possible to extend a size of the physical address space later without changing the hardware.